Chapter 14, Problem 14.41P

How could you use chemical shift and integration data ${}^{\text{1}}\text{H}$ NMR spectroscopy to distinguish between ${\text{CH}}_{\text{3}}{\text{OCH}}_{\text{2}}{\text{CH}}_{\text{2}}{\text{OCH}}_{\text{3}}$ and ${\text{CH}}_{\text{3}}{\text{OCH}}_{\text{2}}{\text{OCH}}_{\text{3}}$? The ${}^{\text{1}}\text{H}$ NMR spectrum of each compound contains only singlets.